Fifteen years after its original release, William Friedkin's "Cruising" has transformed from a political issue to a peculiar cultural document.

The 1980 thriller, about a series of murders set against the background of New York's gay S&M club scene, can be seen as a glimpse of a pre-AIDS gay subculture. Or as an opportunity to see Al Pacino looking uncomfortable in skin-tight pants and a tank top.

Most important, "Cruising" can at last be viewed as a piece of film making. The picture, which begins a one-week revival today at the Roxie, has to stand as one of the most original thrillers of the 1980s. It's a lurid, twisted film that brings you into its world and completely works you over.

SLASHER FILM

On one level "Cruising" is just another slasher movie. A killer is making the rounds of the S&M clubs, picking up guys, tying them up and hacking them to death. The killer (Richard Cox) is tall and thin, and wears the regulation sunglasses, chains, biker jacket and hat. Later we find out he's a graduate student doing his thesis on the roots of the American musical theater. It was either that or have him be an interior decorator, I guess.

Yet despite some crudeness in conception, "Cruising" exists on a level far above a regulation slasher, thanks to its bizarre, one-of-a- kind setting and Friedkin's impassioned direction. Friedkin knows how to make you care and knows how to get you scared. The first killing, presented from the likable victim's point of view, is agonizing to watch.

"Cruising" created an uproar as it was being filmed in New York, and turned out to be the only mainstream Hollywood film to use the gay S&M underworld as a backdrop. In the film, this is an environment rife with menace and possibility, an aggressive, animalistic world completely divorced from the female principle. It's into this world that straight, nice- guy cop Al Pacino goes undercover -- all 145 pounds of him -- in pursuit of the killer.

The rumors were that in the midst of the controversy Pacino became unhappy with the role and played the lead in "Cruising" under duress. If so, duress works fine here. He's a cop without a gun -- and a straight man trying to pass as gay. He plays a man on the other side of the looking glass trying to hang on to his identity while concealing it from the world. No wonder he looks pained. "Cruising" is a unique thriller in that the main source of interest isn't in the cop- and-killer angle, but in the hero's mental state.

STRANGE ATTRACTION

It's clear from the beginning that on some level our hero is drawn to this hardcore scene, but the beauty of the film is that Friedkin draws us into it as well. The scene may be repellent and shocking, yet we understand its power to take this fellow nightly to an edge he might never have explored in the course of a lifetime. He has entered a primal male universe. In contrast, Pacino's sex scenes with his girlfriend (Karen Allen) are dull. They know each other already. Nothing bad can happen. What's the fun in that?

The crime-story aspect is slick but doesn't have as much impact, and when the picture begins to focus on the killer, "Cruising" enters into pretty thin territory. But the movie shifts back to Pacino for an eerie ambiguous finish: a wonderfully chilling close-up of Pacino's reflection staring back at him with strange, cold satisfaction.